Composition of matter and processes for its preparation



Sept. 26, 1950 A. 'r. B. P. SQUIRES 2,523,732

COMPOSITION OF MATTER AND PROCESSES FOR ITS PREPARATION Filed March 27,1950 2 Sheets-Sheet 1 We? mvam'ov. ALAN T. B. F? 569N1 5 Sept. 26, 1950A. 'r. B. P. SQUIRES" 2,523,732

couvosrrxon 0F MATTER AND PROCESSES FOR ITS PREPARATION Filed March 27,1950 2 Sheets-Sheet 2 I mvcu'rok ri llllt T BuR Mil/i171 in UNITEDSTATES PATENT OFFICE COMPOSITION OF MATTER AND PROCESSES FOR ITSPREPARATION Alan Thomas Barrington Parkhurst Squires, Allenton, England,assignor to Rolls-Royce Limited, Derby, England, a British companyOriginal application August 24, 1946, Serial No. 692,898. Divided andthis application March 27, 1950, Serial No. 152,067.

August 30, 1945 4 Claims.

This application is a division of my prior copending application filedAugust 24, 1946, Serial No. 692,898.

This invention concerns production of a new In Great Britain 2continuous stirring, to 220 C. at which temperature a reaction takesplace accompanied by considerable frothing of the mixture. Whilst thisreaction is in progress the temperature of the composition of matter. 5mixture is allowed to rise to 226 C. and it is main- The inventionrelates to a composition which tained at this temperature withcontinuous stiris referred to as a jointing substance. The main ring fora period of 2 to 5 minutes. It is preferapplication of such a substanceis for the purable not to heat the mixture for much longer pose ofjointing or sealing co-operating surfaces, periods than 5 minutes atthis stage. as, for example, in internal combustion engines. The mixtureis then allowed to cool and Jointing substances to which the inventionrethroughout this stage of the process it is being lates, may beprepared to have a low viscosity to continuously stirred until thetemperature falls permit application of the solution to the surface toapproximately 200 C. The mixture is then to be treated, and after theevaporation of solpoured into shallow tinned iron trays and allowedvents which they contain, leave a base medium to coolto roomtemperature, the final product be- Which has a high degree of tackiness.The proping a translucent reddish-brown rubber'like elaserties of lowviscosity for application and tackitic mass.

, ness after application are very desirable in joint- The vulcanizedbase thus obtained may be ing substances. 2O brought into a suitablecondition for use as a According to the invention, a process for thejointing substance by treating the composition preparation of a jointingsubstance comprises with a suitable organic solvent to convert it to theaddition of sulphur to a fatty oil, heating a jelly and then dissolvingthe jelly in a second the mixture at a temperature in excess of 220organic solvent to form a solution or dispersion C. so asto produce avulcanized base, and diswhich is readily capable of being applied to thesolving said base in an organic solvent of a volajoint by means of abrush. For convenience, in tile nature to form a solution or dispersionwhich describin the above conversions in detail, the is in a flowableform to the surface to be treated, composition obtained by the heatingof the sulevaporation of said solvent producing a base phur and thefatty Oil Will be referred to as a medium of a tacky nature. base, thesolution or dispersion applied to the Preferably the fatty oil is castoroil or cod liver surfaces to be joined together will be referred to oil,the temperature to which the mixture is heatas the jointing substance,and the material obed is 226 C. and the organic solvent contains n d y vp r o the Organic lv n s toluene, xylene or solvent naphtha. Other fattyfrom the jointing substance will be referred to as oils such as linseed,cottonseed or rape oil may the jointing medium. The latter possesses the.be used however. same properties as the base with the additional Theuse of the jointing substance in internal property of being very stickyor tacky. Thus, if combustion engines offers particular advantages twometal plates are coated with the substance since the jointing mediumremains plastic and and the, solvent allowed to evaporate, and thepliable when exposed for long periods to templates pressed together andthen pulled apart, peratures up to the melting point of the composithemedium elongates to numerous threads, showtion and since moreover thebase is resistant to ing that it possesses the properties of flowabilitythe action of lubricating oils and fuels. Such a and adhesion, which itis considered necessary jointing substance may be used without the usefor a jointing medium to possess if it is to funcof a joint washer. tionsatisfactorily as a sealing medium.

In carrying the invention into practical eifect The base, prepared asdescribed, melts at 195 the jointing substance is prepared by adding 20C. but does not harden when heated for long parts by weight ofsublimated sulphur (flowers of periods at temperatures below its meltingpoint sulphur) to 100 parts by weight of castor oil, the and it isentirely resistant to the action of lubri. miggture so produced beingcarefully heated, with eating oil and fuel.

The action of various organic solvents towards the base is as follows:

The word insoluble is here used in a broad sense, inasmuch as it coversthose instances where the product is only partially or slightly solublein the solvent in addition to the instances where it is entirelyinsoluble. The word soluble is used to cover an action which may be theforming of a true molecular solution, a colloidal solution or acolloidal dispersion.

Although the base is capable of being dissolved in toluene, xylene andsolvent naphtha these solvents are not sufliciently volatile to ensurerapid drying of the compound when applied to the joint face. However, ithas been found that if the base be first mixed with one of these threesolvents in sufficient quantity it will form a jelly which is soluble inmany of the solvents in which the base alone is insoluble. For example,when 132 parts by weight of the base are added to 100 parts by weight oftoluene and the resultant mix boiled under reflux a homogeneous solutionis obtained in about 12 hours. Upon cooling the solution sets to a softjelly. A suitable laboratory apparatus for boiling the base-toluenemixture under reflux is diagrammatically shown in Figure 1 of theaccompanying drawing. The apparatus comprises a double-wall condenser 3,a flask 4 to receive the mixture and a source of heat (such as the gasburner 5) for the flask i. A stream of coolant enters and leaves thecondenser 3 by conduits 6.

The action on various organic solvents towards the jelly is as follows:

Behaviour of Solvent Jelly Methylated Spirit Insoluble. TrichlorethyleneSoluble. Carbon Tetr'iohlorirl P Do. Methyl Acetate Do. Ethyl A PotatoD0 Butyl Acetate Do. Amyl Ace Do. A nptnne D0. Benzene- Do.

Example I When the solution is intended as a jointing substance forextremely good joints where only a flash of jointing compound isrequired on the surfaces with little or no beading at the edges of thejoint, it has been found most convenient that it be prepared from partsby weight of jelly and 100 parts by weight of carbon 'tetrachloride.Such a solution may be used in tropical climates.

Ewample II When the solution is intended as a jointing substance for theaverage type of commercial joint where a fairly thick layer of jointingcompound is required on the surfaces, it has been found most convenientthat it be prepared from 100 parts by weight of jelly and 15 parts byweight of acetone. Such a mixture may be regarded as ageneral-all-around-purpose solution suitable for use in temperateclimates.

Example III When the solution is intended as a generalall-around-purposejointing substance for application to the average type of commercialjoint in tropical climates, it has been found most convenient that it beprepared from 100 parts by weight of jelly and 40 parts by weight ofcarbon tetrachloride. Such a solution possesses approximately the sameconsistency and drying rate in tropical climates as that of theabovementioned acetone-thinned solution in temperate climates.

When the above solutions are applied to a joint face, the thinners andtoluene evaporate and leave the jointing medium.

The solution which is applied to the joint face and the vapours arisingfrom it during drying thereon are non-inflammable when carbontetrachloride is the thinner, since although toluene is 7 inflammable,the quantity of carbon I tetra-' chloride which is present in thesolution is suflicient to render the mixture as a whole noninflammable.

When acetone is employed as the thinner, the

solution and the vapours arising from it are inbase being subsequentlyheated with tolueneto form a jelly which is diluted with carbontetrachloride or acetone to produce a substance readily capable ofapplication to the joint faces by a brush.

Although in the description above reference is only made to castor oilit is to be understood that other fatty oils may be combined withsulphur to give similar rubber-like elastic compositions the propertiesof each of which depends to a considerable extent upon the oil which isused.

Solutions prepared by the above method were found to be satisfactory asjoint sealing media,

but the stronger solutions possessed a tendency to turn gelatinousduring storage after a period which varied from 2-6 weeks, and in thiscondition they could notbe applied so readily to the surfaces to bejoined. This drawback was not;

noticed with the weak solution, i. e. that having 100 parts by weight ofjelly in 100 parts by weight J of carbon tetrachloride, samples of whichwere found to be quite stable at the end of four months storage.

Inan attempttq overcome the tendency of;

the stronger solutions to. gel, and at the same time to flnda more rapidmethod for dissolving thecastor oil-sulphur product in toluene, it wasfound possible to add the cold toluene to the mglten castor oil-sulphurproduct while the latter. was at. 226 0. immediately the 2 to 5 minutesheating at this temperature was commeted p 5 Since toluene boils. at 110C. under normal atmospheric pressure, it was necessary to adopt asuitable technique in c'arrying out the process.

Example I Example II Example III Castor Oil-sulphur base... 150 150 150Toluene 100 100 100 Carbon 'Ietrachloride 250 100 Acetone 37. 5

A suitable laboratory apparatus by which the cold toluene may be addedto the molten castor oil-sulphur product is diagrammatically shown inFigure 2 of the accompanying drawing. Referring to this figure theapparatus is shown as comprising a flat-bottomed flask l the side wallof which is lagged with asbestos or other heat insulating material as at8. Connected with the flask is a double-wall condenser 9 and a-funnelH), the latter being in communication with the flask by a pipe llincorporating a tap I2. The funnel l and condenser 9 are connectedtogether by a pipe l3 and as is clear from Figure 2 the pipe I3 is aclose fit into'the upper part of the condenser 9 whilst the other end.passes into and just below the neck of the funnel ill. The latter isopen to atmosphere.

The assembly described rests upon a piece of wire-gauze I4 which coversa circular hole in the center of an asbestos sheet H5. The latter issuitably supported above a gas burner 16 and the arrangement is that thediameter of the hole in sheet i5 is slightly larger than the diameter ofthe flat-bottom of the flask I.

' With the apparatus described the following procedure is adopted: Thecastor oil is introduced to the flask 1 (the condenser 9 and funnel Illhaving previously been removed) and the gas burner It is lit so that thetemperature of the oil is raised to 190 C. Thereafter the sulphur isintroduced and this causes the temperature to fall to about 170 C.Thereafter the mixture is heated slowly at the rate of approximately 2C. per minute with constant gentle agitation until atemperature of 226C. is reached. This temperature is then maintained for a duration of 3to 5 minutes at the end of which time the condenser and funnel assemblyis connected to the flask l and the toluene which has previously beenintroduced into the funnel Ill is run on to the hot mass within theflask 1 as quickly as possible by fully opening the tap H2. The toluene,immediately it reaches the molten mass within the flask, vaporizesrapidly and condenses in the condenser 9, but the small increase inpressure developed in the flask l as a consequence forces;

the condensate in the condenser through the pipe [3 and into the funnel[0 from whence it descends into the flask I. This cycle repeats itselfrapidly until ultimately after about seconds all the toluene from thefunnel I0 is in the flask l where;

upon thetap i2 is closed. a

With the procedure described the castor oilsulphur: product 1 dissolvesalmost instantaneously in the toluene and it is believed that this islargecool to approximately C. the required amount of thinner is added tothe mixture withinthe flask i from the funnel l6. It will be appreciatedthat this thinner has previously been introduced to the funnel 10 whilstthe tap l2 remains closed.

' After the thinner has been introduced to the flask l: themixture isboiled for a further period of 30 minutes and at the end of this time itis allowed to cool to room temperature whereupon it is transferred tosuitable storage vessels which should be well sealed.

It is to be noted that the castor oil may 'be heated as quickly aspossible to 190 C. prior to the introduction of sulphur but that oncethis addition has been made it is important that the mixture be heatedat'a controlled rate. Heating from C. to 220 C. over a period of 20 to25 minutes has generally been found satisfactory. If the mixture beheated too quickly at this stage, there is a tendency for it to frothcopiously with loss of sulphur the resulting compound then producedbeing found unsatisfactory. It is important for the same reason that themixture be heated at 226 C. for not longer than 5 minutes.

It has been found that the rate of heating after the addition ofsulphur, and the duration of heating at 226 C. becomes of lessimportance when larger quantities of the compound are being prepared.The times quoted are to be understood therefore as applying to thespecific apparatus shown in Figure 2 in which the flask I has a capacityof 3 litres and the funnel ID a capacity of 500 ccs.

The purpose of lagging the flask l as at 8 is to prevent the formationof a thin layer of undissolved castor oil-sulphur product which wouldotherwise solidify to the side of the flask during the addition of thetoluene.

It will be appreciated, of course, that a plant based upon theprinciples of production described with reference to Figure 2 may bedesigned for industrial manufacture of the compound.

A jointing compound prepared as above described has been found to beeffective for sealing leaks in petrol tanks, protecting rubber cablesagainst fuel and oil, sticking rubber to glass and glass to metal. It isbelieved that compositions prepared in accordance with the presentinvention are capable of many other uses in addition to producingleak-proof joints without the use of packing materials.

I claim:

1. A process for the preparation of jointing composition, which processcomprises adding sulphur to a fatty oil, the sulphur comprising between10% and 43% by weight of the mixture, heating the mixture at atemperature between 220 C. and 240 (3., maintaining the temperature forfrom 2 to 5 minutes to produce a vulcanized 7 base, dissolving ordispersing the base in a volatile, organic solvent chosen from the groupconsisting of toluene, xylene and solvent naphtha and dissolving theresultant mass in benzene for thinning the same to the desiredconsistency for the jointing composition.

2. A process for the preparation of a jointing composition, whichprocess comprises adding approximately 20 parts by weight of sulphur to100 parts by Weight of fatty oil, heating the mixture at a temperaturein excess of 220 C. and raising the same to 226 C., maintaining saidlast mentioned temperature for from 2 to 5 minutes, dissolving ordispersing the base in a volatile, organic solvent chosen from the groupconsisting of toluene, xylene, and solvent naphtha and dissolving theresultant mass in benzene for thinning the same to the desiredconsistency for the jointing composition.

3. A process for the preparation of a jointing composition, whichprocess comprises heating 100 parts by weight of castor oil to 190 0.adding 20 parts by weight of flowers of sulphur thereto with continuousstirring, raising the temperature of the mixture to 226 C. over a periodof 20 to 30 minutes, maintaining the mixture at'226" C. for 2 to 5minutes, dissolving or dispersing the base thus formed in a volatile,organic solvent chosen from the group consisting of toluene, xylene andsolvent naphtha and dissolving the resultant mass in benzene forthinning the same to the desired consistency for the jointingcomposition.

4. A process for the preparation of a jointing composition, whichprocess comprises heating 100 parts by weight of castor oil to 190 C.adding 20 parts by weight of flowers of sulphur thereto with continuousstirring, raising the temperature of the mixture to 226 C. over a periodof 20- to minutes, maintaining the mixture at 226- C. for 2 to 5 minuteswhile agitating the same to produce a vulcanized base and allowing thevulcanized base to cool, adding 132 parts by weight of the base to partsof an organic solvent chosen from the group consisting of toluene,xylene and solvent naphtha and boiling under reflux for 12 hours to forma jelly and upon subsequent cooling, diluting 100 parts by weight of thejelly with between 15 to 100 parts by weight of benzene for thinning thesame to the desired consistency for the jointing composition.

ALAN THOMAS BARRINGTON PARKHURST SQUIRES.

No references cited.

1. A PROCESS FOR THE PREPARATION OF JOINTING COMPOSITION, WHICH PROCESSCOMPRISES ADDING SULPHUR TO A FATTY OIL, THE SULPHUR COMPRISING BETWEEN10% AND 43% BY WEIGHT OF THE MIXTURE, HEATING THE MIXTURE AT ATEMPERATURE BETWEEN 220*C. AND 240*C., MAINTAINING THE TEMPERATURE FORFROM 2 TO 5 MINUTES TO PRODUCE A VULCANIZED BASE, DISSOLVING ORDISPERSING THE BASE IN A VOLATILE, ORGANIC SOLVENT CHOSEN FROM THE GROUPCONSISTING OF TOLUENE, XYLENE AND SOLVENT NAPHTHA AND DISSOLVING THERESULTANT MASS IN BENZENE FOR THINNING THE SAME TO THE DESIREDCONSISTENCY FOR THE JOINTING COMPOSITION.